Immunosuppressants

Immunosuppressants, also called immunomodulators, were first used in people with inflammatory conditions and organ transplants. Doctors eventually found that these drugs helped to improve IBD inflammation. 

What are immunosuppressants?

Immunosuppressants have an effect on the number or function of immune cells. They help suppress the immune system.

They are useful as maintenance therapy, and they can help boost the effectiveness of biologic drugs. If you are taking biologic drugs, your body may want to reject the biologic. Immunosuppressants can suppress your immune system to make your body less likely to form antigens against the biologic.

Examples of immunosuppressants include methotrexate, azathioprine, 6-mercaptopurine, cyclosporine, and tacrolimus.


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How effective are immunosuppressants?

Here is a summary of the effectiveness of immunosuppressants in managing active IBD and preventing relapse during remission:

Active ulcerative colitis

  • The immunosuppressant cyclosporine is effective at inducing remission in active UC.

  • The immunosuppressants azathioprine, 6-mercaptopurine, methotrexate, and tacrolimus are NOT effective at inducing remission in active UC.

Inactive ulcerative colitis (remission) 

  • Azathioprine and 6-mercaptopurine are effective at preventing relapse in inactive UC.

  • Methotrexate is NOT effective at preventing relapse in inactive UC.

Active Crohn's disease

  • Methotrexate is effective at inducing remission in active CD.

  • Azathioprine and 6-mercaptopurine are NOT effective at inducing remission in active CD.

Inactive Crohn's disease (remission) 

  • Azathioprine and 6-mercaptopurine are effective at preventing relapse in inactive CD.

  • Cyclosporine is NOT effective at preventing relapse in inactive CD.

Talk your health care provider or IBD specialist for more information. 


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Side effects and risks of use

Azathioprine and 6-mercaptopurine

Adverse effects of azathioprine and 6-mercaptopurine can include nausea, allergic reactions, acute pancreatitis (inflammation of the pancreas), hepatitis (inflammation of the liver), increased risk of infection, malignancy, and myelosuppression (bone marrow suppression).

Bone marrow is where blood cells are made, and suppression of bone marrow means fewer white blood cells, red blood cells, or blood clotting cells in the body. As bone marrow suppression can happen anytime during therapy, patients are recommended to have regular blood tests to check for leucopenia, which is a reduction of white blood cells. 

If you develop severe flu-like symptoms or abdominal pain while taking azathioprine or 6-mercaptopurine, stop the medication and call your doctor immediately. 

Methotrexate

Adverse effects of methotrexate include hepatoxicity (liver damage), pneumonitis (inflammation of the lung), increased risk of infection, malignancy, alopecia (hair loss), stomatitis (a sore of inflammation inside the mouth), and myelosuppression.

If you develop shortness of breath and cough while on methotrexate, you might be having an allergic reaction and should call your doctor immediately.

Cyclosporine and Tacrolimus

Adverse effects of cyclosporine and tacrolimus include renal toxicity (kidney damage), hypertension, hirsuitism (excessive body hair), headache, opportunistic infections (infection caused by bacteria, viruses, fungi, or protozoa), seizures, and paresthesia (tingling in the legs, arms, hands, or feet).

Immunizations and vaccinations 

If you are taking immunosuppressants, you should avoid having live vaccines from three weeks before starting this type of drug. You should not have vaccines during the time you are on immunosuppressants, up until three to six months after stopping. You should also avoid anyone who has recently had live vaccine, and avoid the nasal flu vaccine.


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